TWI855112B - Edge trimming device - Google Patents

Abstract

[Topic] In an edge trimming device, a wafer is held by a worktable whose surface is free of machining chips. [Solution] An edge trimming device includes: a worktable, an annular groove having an outer diameter smaller than that of the wafer is connected to a suction source to attract and hold the lower surface of the wafer by the annular groove; a cutting unit, a cutting blade is rotated to cut the outer peripheral portion of the wafer held on the worktable in an annular shape; and a cleaning unit, a region of the upper surface of the worktable that is outside the annular groove and the upper surface of the worktable including the annular groove are cleaned. The cleaning unit is positioned on the area of the upper surface of the workbench that is outside the annular groove and the upper surface of the work clamp including the annular groove, and the work clamp is rotated to clean the annular groove and the upper surface.

Description

Edge trimming device

The present invention relates to an edge trimming device for trimming the outer periphery of a wafer.

If the wafer is ground with a grinding stone to reduce the thickness, there is a problem that the chamfered portion of the wafer's periphery becomes a sharp edge, causing the wafer to break from the sharp edge. Therefore, there is an edge trimming device that removes the periphery of the wafer before grinding (see, for example, Patent Document 1 or Patent Document 2).

The edge trimming device makes the grindstone contact the outer peripheral portion of the wafer held by the holding surface of the work chuck, and rotates the wafer to remove the outer peripheral portion. When the processing chips discharged by this edge trimming process enter between the lower surface of the wafer and the holding surface of the work chuck and adhere to the holding surface, the height of the lower surface of the wafer held by the holding surface cannot be constant. Therefore, for example, in the method disclosed in Patent Document 2, when the chamfered portion of the bonded wafer in which the wafer is bonded to the substrate with an adhesive is completely removed, there is a problem that the adhesive located on the bonding surface adheres to the cutting blade and the cutting process cannot be performed.

To solve this problem, an annular groove with an outer diameter slightly smaller than that of the wafer is formed on the flat upper surface of the work chuck, and the annular groove is connected to a suction source, so that the wafer is attracted and held by the annular groove, and most of the upper surface of the work chuck is formed into a sliding surface to prevent processing chips from being attached. Prior art literature Patent literature

Patent document 1: Japanese Patent Publication No. 2010-165802 Patent document 2: Japanese Patent Publication No. 2017-004989

Invention Problems to be Solved

However, there is a problem that processing chips enter between the work chuck and the wafer from the outer periphery of the wafer, and the processing chips adhere to the vicinity of the annular groove on the upper surface of the work chuck, which becomes a problem. Accordingly, the purpose of the present invention is to provide an edge trimming device that can hold a wafer by holding a work chuck without processing chips attached to the surface. Means for solving the problem

According to the present invention, an edge trimming device can be provided, the edge trimming device comprising: a worktable having an annular groove with an outer diameter smaller than the outer diameter of the wafer, and the annular groove is connected to a suction source to attract and hold the lower surface of the wafer by the annular groove; a worktable rotating mechanism to rotate the worktable; a cutting unit to rotate a spindle equipped with a cutting blade to cut the outer peripheral portion of the wafer held on the worktable in an annular shape; and a cleaning unit to clean the upper surface of the worktable. The cleaning unit is positioned at the area on the upper surface of the work clamp that is outside the annular groove and the upper surface of the work clamp that includes the annular groove, and the work clamp is rotated by the work clamp rotating mechanism to clean the area on the upper surface of the work clamp that is outside the annular groove and the upper surface of the work clamp that includes the annular groove.

Preferably, the edge trimming device is further equipped with a horizontal moving mechanism for moving the cutting unit in the axial direction of the spindle, the cutting unit includes a spindle unit and a blade cover, the spindle unit rotates the spindle connected to the mounting seat on which the cutting blade is mounted, and the blade cover surrounds the mounting seat and the cutting blade. The cleaning unit includes a cleaning nozzle mounted on the blade cover and spraying high-pressure water downward, and the horizontal moving mechanism is used to position the landing area of the high-pressure water sprayed from the cleaning nozzle on the upper surface of the work jig that is further outside the annular groove and the upper surface of the work jig including the annular groove for cleaning.

Preferably, the cleaning unit includes a sponge and a sponge nozzle, the sponge nozzle supplies cleaning water to the sponge, and the sponge is positioned on the upper surface of the work clamping table in an area outside the annular groove and the upper surface of the work clamping table including the annular groove, and the sponge is cleaned by supplying cleaning water from the sponge nozzle. Effect of the invention

According to the present invention, since the wafer can be set flat and held by the work chuck which has been cleaned and has no processing chips attached to the upper surface, the depth of the concave portion formed on the outer periphery of the wafer by edge trimming can be set constant. In addition, since the inside of the annular groove of the work chuck can be cleaned, it is possible to prevent the reduction of the suction force of the work chuck which may be caused by the processing chips clogging the annular groove.

In addition, in an edge trimming device in which two cutting units are arranged facing each other, for example, a cleaning nozzle may be provided for each cutting unit as a cleaning unit, and the cleaning effect may be changed by making each cleaning area different. For example, one cleaning nozzle can be made to spray high-pressure water in a cylindrical shape for concentrated cleaning of the area on the upper surface of the work chuck that is outside the annular groove, and another cleaning nozzle can be made to spray high-pressure water in a fan shape for mainly cleaning a large area of the upper surface of the work chuck and the annular groove, thereby more efficiently cleaning the area on the upper surface of the work chuck that is outside the annular groove and the upper surface of the work chuck including the annular groove.

Furthermore, when the cleaning unit includes a sponge and a sponge nozzle for supplying cleaning water to the sponge, the depth of the concave portion formed on the outer periphery of the wafer by edge trimming can be set constant because the sponge is positioned at the area of the upper surface of the work chuck outside the annular groove and the upper surface of the work chuck including the annular groove, and the wafer can be flattened and held by the work chuck that has been cleaned and has no processing chips attached to the upper surface. In addition, since the inside of the annular groove can be cleaned, it is possible to prevent the suction force of the work chuck from being reduced.

The form used to implement the invention

(First embodiment) The edge trimming device 1 shown in FIG. 1 of the present invention (hereinafter referred to as the edge trimming device 1 of the first embodiment) is a device that can trim the edge of a wafer W held on a work clamp 30 by means of a first cutting unit 61 or a second cutting unit 62 having a rotating cutting blade 613. Furthermore, the edge trimming device 1 is not limited to a device that can perform double cutting (two-axis simultaneous cutting) on a wafer W.

The wafer W shown in FIG1 is a semiconductor wafer with a circular shape, for example, made of silicon as a base material, and its front surface Wa has a grid-shaped area on which a device such as an IC (not shown) is formed. The outer periphery of the wafer W is chamfered to form a chamfered portion Wd (see FIG2 ) in a substantially arc-shaped cross section. In addition, the wafer W may be made of gallium arsenide, sapphire, gallium nitride, ceramic, resin, or silicon carbide, etc., in addition to silicon, and may not have a device formed thereon.

As shown in FIG. 2 , the wafer W is formed as a so-called bonded wafer W1, for example. That is, the circular wafer W is bonded to a substrate SB (support substrate) of approximately the same diameter on the front side Wa facing downward in FIG. 2 with a bonding agent SB1 or the like. Therefore, by integrating the wafer W and the substrate SB for processing, the handling of the wafer W can be improved, and the warping or damage of the wafer W during processing can be prevented. The center of the wafer W is approximately the same as the center of the substrate SB.

A cutting feed mechanism 13 for moving the work clamp 30 in the X-axis direction is provided on the base 10 of the edge dressing device 1. The cutting feed mechanism 13 is composed of a ball screw 130 having an axis extending in the X-axis direction, a pair of guide rails 131 arranged parallel to the ball screw 130, a motor 132 for rotating the ball screw 130, and a movable plate 133 that is screwed to the ball screw 130 with an internal nut and whose bottom is slidably connected to the guide rail 131. Furthermore, when the motor 132 rotates the ball screw 130, the movable plate 133 is guided by the guide rail 131 to move in the X-axis direction, and the worktable 30 disposed on the movable plate 133 and attracting and holding the wafer W1 is cut and fed in the X-axis direction as the movable plate 133 moves.

The work clamp 30 shown in FIG2 has a base 30A whose outer shape is circular in a plane view, and an annular protrusion 30B formed of a pure member such as an alloy of ceramic or stainless steel is vertically provided on the upper surface of the base 30A. The upper surface of the annular protrusion 30B is a smooth holding surface 300, and the holding surface 300 attracts and holds the peripheral side area of the lower surface of the substrate SB attached to the front surface Wa of the wafer W.

For example, an annular groove 301 having an outer diameter smaller than that of the substrate SB is formed at a substantially middle position of the annular width of the annular holding surface 300. In addition, a plurality of suction holes 301a are formed at equal intervals in the circumferential direction at the bottom of the annular groove 301, penetrating the annular convex portion 30B and the base portion 30A in the thickness direction (Z-axis direction). A suction flow path 390 such as a resin pipe or a metal pipe is connected to the lower end side of each suction hole 301a, and the suction flow path 390 is connected to a suction source 39 such as a vacuum generating device or an ejector mechanism. Here, the upper surface 300 of the annular convex portion 30B of the work chuck 30, that is, the region outside the annular groove 301 of the holding surface 300 is defined as a region 300a.

Each suction hole 301a is connected to an air source 38, and the air source 38 is composed of a compressor or the like that supplies air to the holding surface 300 of the work chuck 30. For example, when the bonding wafer W1 is to be removed from the work chuck 30 by releasing the suction holding of the bonding wafer W1 by the work chuck 30, the air source 38 supplies compressed air to the suction hole 301a. As a result, the vacuum adsorption force remaining between the holding surface 300 and the bonding wafer W1 can be eliminated by the air sprayed from the suction hole 301a onto the holding surface 300, so that the bonding wafer W1 can be held by a clamp or the like and separated from the holding surface 300.

In the concave space formed by the upper surface of the base 30A and the inner surface of the annular protrusion 30B, a lifting table 31 in the shape of a circular plate in a planar view is arranged. The upper surface of the lifting table 31 is a smooth surface formed by pure components and the like. In addition, the lifting table 31 is movable up and down in the Z-axis direction by the cylinder 310 built into the base 30A. Furthermore, the cylinder 310 may also be an electric cylinder. For example, the upper surface of the lifting table 31 in a non-rising state is flush with the retaining surface 300 of the annular protrusion 30B.

The lifting table 31 is used, for example, to lift the bonded wafer W1 above the holding surface 300 when unloading the bonded wafer W1 from the holding surface 300 after edge trimming of the wafer W attached to the substrate SB held on the holding surface 300, so that a conveying assembly (not shown) can edge clamp the outer periphery of the substrate SB.

As shown in FIG. 1 , the work table 30 is rotatable by a work table rotating mechanism 32 composed of a motor disposed below the work table and a rotating shaft whose axial direction is the Z-axis direction (vertical direction).

On the rear side (-X direction side) of the base 10 shown in FIG1 , a portal support 14 is vertically arranged to cross the moving path of the work clamp 30. On the front surface of the portal support 14, a first horizontal movement mechanism 15 is provided for reciprocating the first cutting unit 61 in the Y-axis direction orthogonal to the X-axis direction and the Z-axis direction.

The first horizontal movement mechanism 15 includes, for example, a ball screw 150 having an axis extending in the Y-axis direction, a pair of guide rails 151 arranged in parallel with the ball screw 150, a motor (not shown) connected to one end of the ball screw 150, and a movable plate 153 whose inner nut is screwed to the ball screw 150 and whose side is slidably connected to the guide rail 151. When the motor (not shown) rotates the ball screw 150, the movable plate 153 is guided by the guide rail 151 and moves in the Y-axis direction, so that the first cutting unit 61 arranged on the movable plate 153 through the first cutting feed mechanism 17 can be horizontally moved in the Y-axis direction (indexing feed).

The first cutting feed mechanism 17 includes: a ball screw 170 that can make the first cutting unit 61 move back and forth in the Z-axis direction, and has an axis extending in the Z-axis direction; a pair of guide rails 171, which are arranged parallel to the ball screw 170; a motor 172, which is connected to the ball screw 170; and a supporting member 173, which supports the first cutting unit 61 and has an internal nut screwed on the ball screw 170 and a side sliding connection on the guide rail 171. When the motor 172 rotates the ball screw 170, the support member 173 is guided by the pair of guide rails 171 to move in the Z-axis direction, and the first cutting unit 61 is fed in the Z-axis direction accordingly.

As shown in FIG. 3 , the first cutting unit 61 includes a spindle unit 61A that rotates a spindle 610 connected to a mounting seat (not shown) on which a cutting blade 613 is mounted, and a blade cover 614 that surrounds the mounting seat (not shown) and the cutting blade 613 .

The spindle unit 61A includes a spindle 610 whose axial direction is the Y-axis direction, a spindle housing 611 fixed to the lower end side of the support member 173 of the first cutting feed mechanism 17 and rotatably supporting the spindle 610, and a motor 612 for rotating the spindle 610. The spindle 610 rotatably accommodated in the spindle housing 611 protrudes from the spindle housing 611 with its front end side toward the -Y direction, and a mounting seat (not shown) is installed on the front end side.

The cutting blade 613 shown in FIG3 is formed in the shape of an annular plate and has a hole in the center for inserting the spindle 610, and is an annular washer-type blade having an annular cutting edge 613b on the outer periphery, wherein the annular cutting edge 613b is formed by fixing diamond abrasives, etc. with a suitable adhesive.

The cutting blade 613 is screwed and locked to the spindle 610 by a fixing nut not shown in the figure, and is fixed and mounted on the spindle 610 by a mounting seat not shown and a fixing nut from both sides in the Y-axis direction, that is, the first cutting unit 61 is assembled as shown in Figures 1 and 3. The rotation center of the cutting blade 613 is roughly consistent with the axis of the spindle 610. In addition, the spindle 610 is driven to rotate by a motor 612 connected to the rear end side of the spindle 610, and the cutting blade 613 rotates accordingly.

The blade cover 614 surrounding the mounting seat and cutting blade 613 (not shown) from above is composed of a blade cover base 614a and a sliding cover 614b. The sliding cover 614b is arranged on the blade cover base 614a and can slide in the X-axis direction relative to the blade cover base 614a.

A nozzle support block 614c is provided on the side surface of the blade cover base 614a on the +X direction side, and a shower nozzle 651 is provided on the nozzle support block 614c for spraying cutting water from the radial outer side of the cutting blade 613 toward the cutting blade 613. The shower nozzle 651 is connected to a water supply source 68 that can deliver pure water or the like through a resin pipe 680. As shown in FIG. 4 , the cutting water supplied from the shower nozzle 651 to the cutting blade 613 mainly serves to cool the cutting blade 613.

As shown in FIG3 , two cutting water nozzles 652 are provided on the nozzle support block 614c, for example, and the cutting water nozzles 652 spray and supply cutting water from obliquely upward toward the contact portion (processing point) between the cutting blade 613 and the wafer W. The two cutting water nozzles 652 are arranged symmetrically in the Y-axis direction with the cutting blade 613 as a symmetry axis, for example, in a planar view. The cutting water nozzles 652 are connected to a water supply source 68 through a resin pipe 681. As shown in FIG4 , the cutting water supplied from the two cutting water nozzles 652 to the processing point mainly achieves the following function: cleaning and removing the cutting chips generated at the processing point from the wafer W.

The sliding cover 614b is connected to the blade cover base 614a through an air cylinder (not shown) and is formed to be slidable in the X-axis direction. After the cutting blade 613 is mounted on the spindle 610, the blade cover 614 is mounted on the front surface of the spindle housing 611 on the -Y direction side, and the sliding cover 614b in the opened state is slid toward the +X direction to cover the blade cover 614, so that the cutting blade 613 can be accommodated in the opening in the approximate center of the blade cover 614, and the first cutting unit 61 can cut the wafer W.

As shown in FIG3 , the sliding cover 614b supports a pair of blade cooling nozzles 653 in a substantially L-shaped manner when viewed from the -Y direction. The pair of blade cooling nozzles 653 extend downward through the sliding cover 614b and then extend parallel to each other in the +X direction across the lower portion of the cutting blade 613. The upper end of each of the pair of blade cooling nozzles 653 is connected to the water supply source 68 through a resin pipe 683. As shown in FIG4 , the pair of blade cooling nozzles 653 have a plurality of slits 653a facing the side of the cutting blade 613, and the cutting blade 613 can be cooled and cleaned by cutting water sprayed from the slits 653a.

The edge trimming device 1 shown in FIG. 1 is provided with a cleaning unit 7, and the cleaning unit 7 cleans the area 300a outside the annular groove 301 of the holding surface 300 (i.e., the upper surface 300) of the work clamp 30 and the upper surface 300 of the work clamp 30 including the annular groove 301. The cleaning unit 7 shown in FIGS. 1 and 3 is provided with a cleaning nozzle 70, for example, which is installed on the blade cover 614 and sprays high-pressure water in the downward direction (-Z direction). Hereinafter, the cleaning unit 7 is set as a cleaning unit 7 of the first embodiment having the cleaning nozzle 70.

For example, the cleaning nozzle 70 is supported by a cleaning nozzle support block 71 installed on the side surface of the sliding cover 614b on the -X direction side. The cleaning nozzle 70 is formed by forming a nozzle 700 formed at its lower end into a rectangular shape with the long side direction being the Y-axis direction, as shown in FIG. 4, and is formed so that the cleaning water can be sprayed downward from the nozzle 700 in a generally fan-shaped expansion. The upper end of the cleaning nozzle 70 is connected to the water supply source 68 through a resin pipe 72. Furthermore, the cleaning nozzle 70 may be connected to an air supply source (not shown) and may spray a double fluid mixed with water supplied from the water supply source 68 and air supplied from the air supply source. Furthermore, the cleaning nozzle 70 may spray cleaning water imparted with ultrasonic vibration.

As shown in FIGS. 1 and 3 , a calibration unit 11 is provided near the first cutting unit 61. The calibration unit 11 detects the position of the chamfered portion Wd to be cut of the wafer W held on the work clamp 30. The calibration unit 11 performs image processing such as pattern matching based on the image captured by the camera 110, and can detect the coordinate position of the chamfered portion Wd.

A second horizontal movement mechanism 16 is provided on the front surface of the portal support 14 shown in FIG1 , for example, to reciprocate the second cutting unit 62 in the Y-axis direction. The second horizontal movement mechanism 16 includes, for example, a ball screw 160 having an axis extending in the Y-axis direction, a pair of guide rails 151 provided parallel to the ball screw 160, a motor 162 connected to the ball screw 160, and a movable plate 163 whose inner nut is screwed to the ball screw 160 and whose side is slidably connected to the guide rail 151. Furthermore, when the motor 162 rotates the ball screw 160, the movable plate 163 is guided by the guide rail 151 and moves in the Y-axis direction, and the second cutting unit 62 arranged on the movable plate 163 can be horizontally moved in the Y-axis direction (indexing feed) through the second cutting feed mechanism 18.

The second cutting feed mechanism 18 includes: a ball screw 180 that can make the second cutting unit 62 move back and forth in the Z-axis direction, and has an axis extending in the Z-axis direction; a pair of guide rails 181, which are arranged parallel to the ball screw 180; a motor 182, which is connected to the ball screw 180; and a supporting member 183, which supports the second cutting unit 62 and has an internal nut screwed on the ball screw 180 and a side sliding connection on the guide rail 181. Furthermore, when the motor 182 rotates the ball screw 180, the support member 183 is guided by the pair of guide rails 181 to move in the Z-axis direction, and the second cutting unit 62 is fed in the Z-axis direction accordingly.

The second cutting unit 62 is disposed to face the first cutting unit 61 in the Y-axis direction. Since the first cutting unit 61 and the second cutting unit 62 are configured substantially the same, a detailed description of the second cutting unit 62 is omitted.

The blade cover 614 of the second cutting unit 62 is also provided with a cleaning unit 7. The cleaning unit 7 provided with the blade cover 614 of the second cutting unit 62 has a cleaning nozzle 73 supported by a cleaning nozzle support block 71. As shown in FIG5 , the cleaning nozzle 73 has a spray port 730 formed at its lower end portion formed into, for example, a circular shape, and is formed so that cleaning water can be sprayed downward in a roughly cylindrical shape from the spray port 730. The upper end of the cleaning nozzle 73 is connected to the water supply source 68 shown in FIG3 through a resin pipe not shown. For example, the cleaning nozzle 73 may be connected to an air supply source (not shown) and may spray a double fluid mixed with water supplied from the water supply source 68 and air supplied from the air supply source. In addition, the cleaning nozzle 73 may spray cleaning water to which ultrasonic vibration is imparted. Furthermore, the cleaning nozzle 70 may be provided in the second cutting unit 62, and the cleaning nozzle 73 may be provided in the first cutting unit 61.

Furthermore, the shower nozzle 651 shown in FIG. 3 , the two cutting water nozzles 652 , the pair of blade cooling nozzles 653 , the cleaning nozzle 70 , and the cleaning nozzle 73 shown in FIGS. 5 and 6 are connected to or not connected to the water supply source 68 by switching on and off valves not shown in the figure that are respectively arranged in the connected resin pipes.

Below, with respect to the edge trimming device 1 shown in FIG. 1 , after cleaning the area 300a of the upper surface 300 (holding surface 300) of the work chuck 30 that is outside the annular groove 301 and the upper surface 300 of the work chuck 30 including the annular groove 301, the cleaned work chuck 30 is used to hold the bonded wafer W1, and the chamfered portion Wd of the peripheral portion of the wafer W is annularly trimmed.

During the cleaning of the worktable 30, the worktable 30 shown in FIG. 1 which does not hold the bonded wafer W1 is first moved in the X-axis direction by the cutting feed mechanism 13, and the worktable 30 is positioned below the cleaning unit 7 with the blade cover 614 provided on the first cutting unit 61 and the cleaning unit 7 with the blade cover 614 provided on the second cutting unit 62.

Since the control unit (not shown) that controls the entire device of the edge trimming device 1 knows the center position of the work clamp 30, it can also know the position of the annular groove 301 that is away from the center position by a predetermined distance in the radial direction. In addition, the first horizontal moving mechanism 15 sets the center position of the work clamp 30 as a reference, and moves the cleaning nozzle 70 of the cleaning unit 7 disposed on the blade cover 614 together with the first cutting unit 61 in the Y-axis direction, so that the center of the groove width of the annular groove 301 is roughly consistent with the center of the cleaning nozzle 70. As a result, as shown in FIG. 6 , the landing area of the high-pressure cleaning water ejected from the cleaning nozzle 70 and expanding downward in a roughly fan-shaped manner as viewed from the front side (+X direction side) of the paper surface can be positioned between the annular groove 301 and the holding surface 300 of the work clamp 30.

In addition, the second horizontal moving mechanism 16 sets the center position of the work clamp 30 as a reference, so that the cleaning nozzle 73 of the cleaning unit 7 equipped with the blade cover 614 moves in the Y-axis direction together with the second cutting unit 62 to position the area 300a further outside the annular groove 301 and the center of the cleaning nozzle 73 that sprays cleaning water in a cylindrical shape downward.

Next, the first cutting feed mechanism 17 shown in FIG. 1 moves the cleaning nozzle 70 in the Z-axis direction and positions it to a suitable height, and the second cutting feed mechanism 18 moves the cleaning nozzle 73 in the Z-axis direction and positions it to a suitable height. In this state, the water supply source 68 shown in FIG. 6 supplies high-pressure water to the cleaning nozzle 70. As shown in FIG. 6, the cleaning water can be expanded downward from the spray port 700 of the cleaning nozzle 70 in a roughly fan-shaped manner, and the cleaning water mainly cleans and removes the cutting chips attached to the groove bottom and side walls of the annular groove 301 or the cutting chips attached to the retaining surface 300 (upper surface 300) over a wide range. In addition, high-pressure water is supplied to the cleaning nozzle 73 by the water supply source 68, and as shown in Figure 6, the cleaning water is sprayed downward in a cylindrical shape from the nozzle 730 of the cleaning nozzle 73, and the area 300a of the retaining surface 300 that is further outside the annular groove 301 is cleaned intensively by the cleaning water in a pinpoint manner, thereby removing cutting chips and the like attached to the area 300a.

Furthermore, the worktable 30 can be rotated at a predetermined rotation speed along with the worktable rotating mechanism 32, and the entire circumference of the annular groove 301 and the entire circumference of the holding surface 300 can be cleaned without omission by the cleaning water sprayed from the cleaning nozzle 70 and the cleaning water sprayed from the cleaning nozzle 73.

After the entire circumference of the annular groove 301 and the entire circumference of the holding surface 300 are cleaned for a predetermined time, especially the entire circumference of the area 300a outside the annular groove 301 is cleaned intensively, the water supply source 68 stops supplying water to the cleaning nozzles 70 and 73. Thereafter, for example, the work table 30 is dried by rotation or by spraying air from the cleaning nozzles 70 and 73 connected to an air source not shown.

Next, the edge trimming process of the chamfered portion Wd of the wafer W shown in FIG. 1 is started. First, the center of the wafer W is set to be roughly consistent with the center of the holding surface 300 of the work chuck 30, and the bonded wafer W1 is placed on the holding surface 300 with the substrate SB facing downward so as to block the annular groove 301. In addition, the suction force generated by driving the suction source 39 shown in FIG. 7 is transmitted to the holding surface 300 through the suction hole 301a and the annular groove 301, so that the work chuck 30 attracts and holds the peripheral area of the substrate SB attached to the lower surface Wa (front surface Wa) of the wafer W on the holding surface 300. Furthermore, the bonded wafer W1 is formed into a state where it is placed on the upper surface of the lifting table 31.

The cutting feed mechanism 13 shown in FIG. 1 moves the worktable 30 in the X-axis direction, and the first horizontal moving mechanism 15 moves the camera 110 of the calibration unit 11 in the Y-axis direction, so that the worktable 30 is positioned at a predetermined position in such a manner that the chamfered portion Wd formed on the outer periphery of the wafer W falls within the photographing area of the camera 110. The camera 110 photographs the chamfered portion Wd of the wafer W, and the calibration unit 11 determines the position of the edge coordinates of the chamfered portion Wd of the wafer W based on the photographed image.

For example, after the position of the edge coordinates of the chamfered portion Wd of the wafer W is detected as described above, the bonded wafer W1 held on the work clamp 30 is positioned, for example, below the cutting blade 613 of the first cutting unit 61. Then, the first horizontal moving mechanism 15 sets the position of the edge coordinates of the chamfered portion Wd of the wafer W obtained by the edge calibration method as a reference, and as shown in FIG. 7, the first cutting unit 61 is moved in the Y-axis direction to position the cutting blade 613 at a radially inner position corresponding to a predetermined distance from the chamfered portion Wd of the wafer W. That is, for example, the cutting blade 613 is positioned so that about 2/3 of the lower end surface of the cutting blade 613 contacts the chamfered portion Wd of the wafer W.

Then, the main shaft 610 rotates at high speed in the counterclockwise direction when viewed from the +Y direction side, and the cutting blade 613 fixed to the main shaft 610 rotates at high speed in the counterclockwise direction when viewed from the +Y direction side. In addition, the first cutting unit 61 is lowered by the first cutting feed mechanism 17 shown in FIG. 1, and the cutting blade 613 cuts into the back side Wb of the wafer W to a predetermined depth. The cutting depth of the cutting blade 613 is such that, for example, the chamfered portion Wd is completely removed, but the cutting blade 613 does not reach the contact agent SB1, or cuts into it slightly. After the cutting blade 613 is cut and fed to a predetermined height position, the worktable 30 is rotated 360 degrees counterclockwise when viewed from the +Z direction side while the cutting blade 613 is continuously rotated, thereby cutting the entire circumference of the chamfered portion Wd of the wafer W. Furthermore, the chamfered portion Wd of the wafer W can also be subjected to dual edge trimming by the first cutting unit 61 and the second cutting unit 62.

In the edge trimming of the chamfered portion Wd of the wafer W, the cutting water is supplied to the cutting blade 613 from the radial outer side of the cutting blade 613 by the shower nozzle 651 shown in FIG. 3 and FIG. 4, and the cutting blade 613 is mainly cooled. In addition, the cutting water is supplied to the contact portion between the cutting blade 613 and the wafer W by two cutting water nozzles 652, and the contact portion is mainly cooled by the cutting water and the cutting chips generated at the contact portion are cleaned and removed. In addition, the cutting blade 613 can be cooled by supplying cutting water to the cutting blade 613 from the thickness direction (Y-axis direction) of the cutting blade 613 by a pair of blade cooling nozzles 653.

As described above, the edge trimming device 1 of the present invention has a cleaning unit 7 for cleaning the area 300a of the upper surface 300 of the work clamp 30 that is outside the annular groove 301 and the upper surface 300 of the work clamp 30 that includes the annular groove 301, and by positioning the cleaning unit 7 at the area 300a and the upper surface 300 of the work clamp 30 that includes the annular groove 301, and rotating the work table to clean the edge trimming device 1. The rotating mechanism 32 rotates the work table 30 to clean the area 300a and the upper surface 300 of the work table 30 including the annular groove 301, and the bonded wafer W1 can be set flat and held by the cleaned work table 30 with no cutting chips attached to the upper surface 300, so that the depth of the concave portion formed by the edge trimming process of the chamfered portion Wd of the outer periphery of the wafer W can be set constant. In addition, since the inside of the annular groove 301 can be cleaned, it is possible to prevent the reduction of the suction force of the work table 30 that may be caused by the clogging of the annular groove 301 with cutting chips.

In the edge trimming device 1 of the present invention, the first embodiment of the cleaning unit 7 is a cleaning nozzle 70, 73 installed on the blade cover 614 and spraying high-pressure water in the downward direction, and the landing area of the high-pressure water sprayed from the cleaning nozzle 70 is positioned at the area 300 on the upper surface 300 of the work clamp 30 that is further outside the annular groove 301 by the first horizontal moving mechanism 15. a. By rotating the work chuck 30 while cleaning the upper surface 300 of the work chuck 30 including the annular groove 301, the wafer W1 can be flattened and held by the cleaned work chuck 30 with no processing chips attached to the upper surface 300, so that the depth of the concave portion formed by the edge trimming process of the chamfered portion Wd of the wafer W can be set constant. In addition, since the inside of the annular groove 301 can be cleaned, it is possible to prevent the reduction of the attraction of the work chuck 30 that may be caused by the processing chips clogging the annular groove 301. In addition, in the edge trimming device 1 in which the first cutting unit 61 and the second cutting unit 62 are arranged in two opposing manners as in the first embodiment, for example, the first cutting unit 61 can be provided with a cleaning nozzle 70 as the cleaning unit 7, and the second cutting unit 62 can be provided with a cleaning nozzle 73 as the cleaning unit 7, so that each cleaning area can be made different to change the cleaning effect. For example, one cleaning nozzle 73 can be used to spray high-pressure cleaning water in a cylindrical shape and reach the area 300a for concentrated cleaning of the upper surface 300 of the work clamp 30 that is further outside the annular groove 301, and another cleaning nozzle 70 can be used to spray high-pressure cleaning water in a roughly fan shape for large-scale cleaning of the upper surface 300 and the annular groove 301 of the work clamp 30, so that the annular groove 301 and the upper surface 300 of the work clamp 30 can be cleaned more efficiently without any uncleaned parts.

Furthermore, the water supply source 68 constituted by a pump or the like may not be of a type that can deliver high-pressure water to the cleaning nozzles 70, 73, for example. The cleaning nozzles 70, 73 may be connected to an air supply source in addition to the water supply source 68, and, for example, air may be mixed in each nozzle, and a double fluid may be ejected from each nozzle, and the water droplets ejected to the landing point in the cleaning area may be set to high pressure by the air pressure.

2. Second Implementation Form The edge trimming device 1A of the second implementation form shown in FIG8 is a device in which a part of the components of the edge trimming device 1 of the first implementation form shown in FIG1 is modified. The following describes the parts of the edge trimming device 1A of the second implementation form that are different from the edge trimming device 1 of the first implementation form.

The edge trimming device 1A includes a cleaning unit 8 of the second embodiment. The cleaning unit 8 replaces the cleaning unit 7 of the edge trimming device 1 of the first embodiment with the cleaning nozzle 70 and includes a sponge 80 and a sponge nozzle 81 for supplying cleaning water to the sponge 80.

For example, a support bridge 88 is vertically provided on the base 10 of the edge trimming device 1A so as to cross the moving path of the work clamp 30, and the cleaning unit 8 is mounted on the support bridge 88. The cleaning unit 8 can also be reciprocated in the Y-axis direction on the support bridge 88 by means of a slider (not shown). The spray port of the sponge nozzle 81 is opened toward the sponge 80 and is connected to the water supply source 68.

The type of the sponge 80 is not particularly limited, and for example, polyvinyl alcohol (PVA) sponge can be used. The sponge 80 is formed into, for example, a cylindrical shape, and can be moved up and down in the Z-axis direction by a sponge lifting mechanism 84 installed on a supporting bridge 88. The shape of the sponge 80 is not limited in this example.

The sponge lifting mechanism 84 may be, for example, a cylinder, and includes a cylindrical cylinder tube 840 having a piston (not shown) inside, and a piston rod 841 which can be inserted into the cylinder tube 840 and mounted on the piston at the upper end. The sponge 80 is detachably mounted on the lower end of the piston rod 841.

For example, an air nozzle 86 extending in the Y-axis direction is installed on the supporting bridge 88. The air nozzle 86 has a length, for example, longer than the outer diameter of the work jig 30, and has a plurality of slits 860 facing downward on its side. Furthermore, the air nozzle 86 can dry the holding surface 300 or the inside of the annular groove 301 of the work jig 30 by injecting compressed air from the slits 860. The air nozzle 86 is composed of a compressor or the like, and is connected to an air source 869 that can supply compressed air through a resin pipe or the like.

Below, with respect to the edge trimming device 1A shown in FIG. 8 , after the annular groove 301 of the work chuck 30 and the area 300a on the upper surface of the work chuck 30 that is outside the annular groove 301 are cleaned, the wafer W1 is held bonded with the cleaned work chuck 30, and the chamfered portion Wd of the peripheral portion of the wafer W is annularly trimmed.

In the cleaning of the work chuck 30, first, the work chuck 30 shown in FIG. 8 without holding the bonded wafer W1 is moved in the X-axis direction by the cutting feed mechanism 13, and the work chuck 30 is positioned below the sponge 80 of the cleaning unit 8. In this way, the sponge 80 can be positioned so as to substantially cross the region 300a of the upper surface 300 of the work chuck 30 that is outside the annular groove 301 and the upper surface 300 of the work chuck 30 including the annular groove 301 in the groove width direction.

Next, the sponge lifting mechanism 84 shown in FIG8 lowers the sponge 80, and as shown in FIG9, the deformed sponge 80 contacts the groove bottom of the annular groove 301 of the work clamp 30 and the area 300a of the holding surface 300 that is further outside the annular groove 301. In addition, the sponge 80 absorbs the cleaning water sprayed from the sponge nozzle 81 by sending cleaning water to the sponge nozzle 81 through the water supply source 68, and the sponge 80 swells and has elasticity. In addition, the sponge 80 can also be configured so that it will not swell even if it absorbs cleaning water. Furthermore, washing water may be directly supplied from the sponge nozzle 81 to the annular groove 301 and the area 300a of the work chuck 30.

Furthermore, the table rotating mechanism 32 rotates the worktable 30 at a predetermined rotation speed, and the sponge 80 supplied with cleaning water can clean the entire circumference of the annular groove 301 and the entire circumference of the holding surface 300, thereby removing attached cutting chips and the like.

After the entire circumference of the annular groove 301 and the holding surface 300, especially the entire circumference of the area 300a outside the annular groove 301, is cleaned for a predetermined time, the water supply source 68 stops supplying water to the sponge nozzle 81. The sponge lifting mechanism 84 raises the sponge 80 and moves it away from the working clamping table 30.

Next, the work table 30 is moved in the X-axis direction below the air nozzle 86 by the cutting feed mechanism 13 shown in FIG. 1 , and high-pressure air is sprayed from the air nozzle 86 toward the holding surface 300 of the work table 30. As a result, the cleaning water still attached to the holding surface 300 and the annular groove 301 can be blown away by the air, and the holding surface 300 and the annular groove 301 can be dried. Furthermore, for example, the work table 30 can be dried by rotational drying by rotating, or by spraying air from a sponge nozzle 81 connected to an air source not shown in the figure.

Next, the edge trimming process of the wafer W is started. The edge trimming of the wafer W is performed in the same manner as in the edge trimming apparatus 1 of the first embodiment described above.

In the edge trimming device 1A of the second embodiment of the present invention, since the cleaning unit 8 is provided with the sponge 80 and the sponge nozzle 81 for supplying cleaning water to the sponge 80, the sponge 80 is positioned between the area 300a on the upper surface 300 of the work clamp 30 that is outside the annular groove 301 and the work clamp including the annular groove 301. The upper surface 300 of the wafer W is cleaned by the sponge 80 supplied with cleaning water from the sponge nozzle 81, and the worktable 30 which has been cleaned and has no processing chips attached to the upper surface 300 is set flat and held, so that the depth of the concave portion formed by the edge trimming process of the chamfered portion Wd of the outer periphery of the wafer W can be set constant. In addition, since the inside of the annular groove 301 can be cleaned, it is possible to prevent the reduction of the suction force of the worktable 30 which may be caused by the clogging of the annular groove 301 with the cutting chips.

Furthermore, the edge trimming device 1 of the present invention is not limited to the first and second embodiments, and the various structures of the device illustrated in the attached drawings are not limited thereto, but can be appropriately modified within the scope of the effect of the present invention. For example, the edge trimming device 1 of the first embodiment can also have the air nozzle 86 of the edge trimming device 1A of the second embodiment.

1,1A: Edge trimming device 10: Base 11: Calibration unit 110: Camera 13: Cutting feed mechanism 130,150,160,170,180: Ball screw 131,151,171,181: Guide rail 132,162,172,182,612: Motor 133,153,163: Movable plate 14: Door support 15: 1st horizontal movement mechanism 16: 2nd horizontal movement mechanism 17: 1st cutting feed mechanism 1 73,183: Support member 18: Second cutting feed mechanism 30: Work clamp 30A: Base 30B: Annular convex portion 300: Holding surface (upper surface) of work clamp 300a: Area outside the annular groove 301: Annular groove 301a: Suction hole 31: Lifting table 310: Cylinder 32: Work table rotation mechanism 38,869: Air source 39: Suction source 390: Suction flow path 61: First cutting unit 61A: Spindle unit 610: Spindle 611: Spindle housing 613: Cutting blade 613b: Cutting edge 613a: Fixed flange 614: Blade cover 614a: Blade cover base 614b: Sliding cover 614c: Nozzle support block 62: Second cutting unit 651: Spray nozzle 652: Cutting water nozzle 653: Blade cooling nozzle 653a,860: Slit 68: Water supply source 680,681,683,72: Resin pipe fittings 7,8: Cleaning unit 70,73: Cleaning nozzle 700,730: Nozzle 71: Cleaning nozzle support block 80: Sponge 81: Sponge nozzle 84: Sponge lifting mechanism 840: Cylinder tube 841: Piston rod 86: Air nozzle 88: Support bridge SB: Substrate SB1: Adhesive W: Wafer Wa: Front surface of wafer Wb: Upper surface (back surface) of wafer Wd: Chamfered part W1: Bonding wafer X,Z,+X,-X,+Y,-Y,+Z,-Z: Direction

FIG. 1 is a perspective view showing an example of an edge trimming device having a cleaning nozzle in a cleaning unit. FIG. 2 is a cross-sectional view showing an example of the structure of a work clamp. FIG. 3 is a perspective view showing an example of a cleaning unit composed of a first cutting unit and a cleaning nozzle. FIG. 4 is a schematic plan view showing the structure and arrangement position of a shower nozzle, two cutting water nozzles, a pair of blade cooling nozzles, and a cleaning nozzle of the first cutting unit. FIG. 5 is a schematic plan view showing the structure and arrangement position of a shower nozzle, two cutting water nozzles, a pair of blade cooling nozzles, and a cleaning nozzle of the second cutting unit. FIG6 is a cross-sectional view showing a state in which a cleaning unit equipped with a cleaning nozzle cleans the area outside the annular groove and the upper surface of the work chuck including the annular groove while rotating the work chuck. FIG7 is a cross-sectional view showing a state in which a wafer is held by attracting the work chuck whose upper surface has been cleaned outside the annular groove and the upper surface including the annular groove, and the edge of the chamfered portion of the wafer is trimmed by the first cutting unit. FIG8 is a perspective view showing an example of an edge trimming device equipped with a sponge in the cleaning unit. 9 is a cross-sectional view showing a state in which a region on the upper surface of the work clamp outside the annular groove and the upper surface of the work clamp including the annular groove are cleaned while the work clamp is rotated in the cleaning unit equipped with a sponge.

1: Edge trimming device

10: Base

11: Calibration unit

110: Camera

13: Cutting feed mechanism

130,150,160,170,180: ball screw

131,151,171,181:Guide rails

132,162,172,182: Motor

133,153,163: Movable plate

14: Door-type pillars

15: 1st horizontal movement mechanism

16: Second horizontal movement mechanism

17: 1st cutting feed mechanism

173,183: Support components

18: Second cutting feed mechanism

30: Workbench

300: Holding surface of the work clamp (upper surface)

301: annular groove

301a: Suction hole

31: Lifting workbench

32: Workbench rotation mechanism

61: 1st cutting unit

61A: Spindle unit

610: Main axis

611: Spindle housing

613: Cutting blade

62: 2nd cutting unit

7: Washing unit

70: Clean the nozzle

71: Clean the nozzle support block

73: Clean the nozzle

614: Blade cover

W: Wafer

Wa: front side of the wafer

Wb: upper surface (back side) of the wafer

SB: Base material

W1: Wafer bonding

+X,-X,+Y,-Y,+Z,-Z: Direction

Claims (1)

An edge trimming device comprises: a worktable having an annular groove with an outer diameter smaller than that of a wafer, the annular groove being connected to a suction source so as to attract and hold the lower surface of the wafer by the annular groove; a worktable rotating mechanism for rotating the worktable; a cutting unit for rotating a spindle equipped with a cutting blade to annularly cut the outer peripheral portion of the wafer held on the worktable; a horizontal moving mechanism for moving the cutting unit in the axial direction of the spindle; and a cleaning unit for cleaning the area of the upper surface of the worktable that is outside the annular groove and the upper surface of the worktable that includes the annular groove, the cutting unit comprising a spindle unit and a blade. The spindle unit rotates the spindle connected to the mounting seat on which the cutting blade is mounted, and the blade cover surrounds the mounting seat and the cutting blade. The cleaning unit includes a cleaning nozzle installed on the blade cover and spraying high-pressure water downward. The horizontal moving mechanism positions the landing area of the high-pressure water sprayed from the cleaning nozzle at the workpiece. The upper surface of the work clamping table is cleaned by cleaning the area outside the annular groove and the upper surface of the work clamping table including the annular groove, and the work clamping table is rotated by the work clamping table rotating mechanism to clean the area outside the annular groove and the upper surface of the work clamping table including the annular groove.

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